Sorry folks, mounting birch panels to a frame will not prevent warping. But take heart because warping can be prevented by prepping both sides with which ever primer you use first unless you go with gesso then you need both the gesso and your first layer of oil prime/ground on both sides.
I asked Gamblin tech help about this topic; here's their reply (their contact link at the end)
Thank you for contacting us.
There are several different panels that may be used
for oil painting- some are composites, while others are made in ply
layers. For panel types that require sealing, we recommend a
50/50 Galkyd/Gamsol mixture. (PVA Size is best for sealing stretched fabric and heavy water media paper.)
Brush on the Galkyd/Gamsol mixture liberally.
Allow to soak in several minutes.
Wipe away excess medium that is not absorbed and allow panel to dry overnight.
If painting directly on the panel without a primer coat, apply a second sealing coat to further reduce absorbency.
For a bright white surface, apply two thin coats of Gamblin Oil Painting Ground.
Baltic Birch or other cabinet-grade plywood- seal surface, back and sides are
optional but recommended.
Cradled Birch- seal surface, framework stabilizes thin panel so sealing back
and sides is optional.
Untempered Hardbord- sand lightly, seal front, back & sides.
Tempered Hardboard- (e.g. Masonite) degrease first by wiping down with Gamsol
or rubbing alcohol, allow solvent to evaporate, sand lightly, seal surface.
Ampersand Hardbord- sealing is optional due to its proprietary low-oil tempering.
MDF- (medium density fiberboard) seal front, back and sides.
Acrylic Gesso Primed Panels- sealing not required. Oil Ground may be applied
on top of acrylic gesso for an improved painting surface.
lightly sand surface and wipe down with Gamsol or rubbing alcohol.
No sealing is required if painting directly on the aluminum. For a
bright white non-absorbent ground, apply two thin coats of Oil Ground
rolled on with a small diameter, 4” low-nap paint roller.
Oil Ground should be applied very thinly. Oil Ground may be diluted with
1oz Gamsol for every 16oz of Ground to improve the ease of application and encourage thin layers.
Spread the ground on the wooden panel
initially using a plastic squeegee. Follow up with a 4 ½” wide x ¼” low
nap paint roller to even out the ground.
first coat should be touch dry in 1-3 days. A second coat takes
another 3-5 days to cure in warm, dry weather and 5-7 days in cool
and/or humid weather. Cool Temperatures and/or high humidity may add
several days’ dry time. Generally, allow for 7-10 days
from start to finish before painting on Oil Ground-primed panels.
Again, the thinner the layers, the faster Oil Ground will dry.
Once you have applied 1-2 coats, you simply wait until the ground has dried and then you can immediately start painting.
Cleaning Oil Ground from a Paint Roller
It is difficult to achieve an appropriately thin
layer of Oil Ground using a brush. The small diameter paint rollers are
far more effective and easier on rigid supports. I usually prime a
bunch of panels all in the same session. That
way I only have to do a modest job of cleaning the roller and wrap it
up in plastic until the panels are dry enough for a second coat. After
the second and final coat, the paint roller is well-used and I just
throw it away.
Roll out as much remaining Oil Ground as possible on scrap board or cardboard.
- Drizzle* Gamsol or other odorless mineral spirits into the roller and roll out on a stack of paper towels.
- Repeat until the roller is clean.
Limit your exposure to solvent, by allowing the
scrap board and paper towels to dry outdoors before disposing of in
*Tip: Decant Gamsol into a plastic bottle for
easy dispensing. I use a camp stove funnel to do this. Gamsol is such a
mild solvent, it will not harm a plastic bottle.
I hope this email helps. If other questions come up, please let me know. We appreciate your decision to use our materials.
Mary Weisenburger | Product Specialist | Gamblin Artists Colors | t 503.235.1945
x19 | gamblincolors.com